The invention concerns an inch rule for reading off distances.
Inch rules are also known as yardsticks or measuring rods and are used inter alia in building construction to ascertain distances of construction parts or to mark distances on surfaces.
Known inch rules suffer from the disadvantage that they cannot be used in twilight, at night or in a dark area.
German patent document DE 20 2007 006 460 U1 discloses a measuring device which can be used even at twilight, at night or in a dark area. In particular that publication discloses a measuring tape which is accommodated in a housing. A lighting device is incorporated into the housing, the lighting device shining laterally on the measuring tape and thus making it possible to use it even at twilight or at night.
Measuring tapes, however, suffer from the disadvantage that when measuring the distance between two construction parts the tapes possibly sag or ‘kink’, which falsifies the measurement result.
Exemplary embodiments of the present invention an inch rule that makes it possible to perform measurements even under unfavorable lighting conditions.
For that purpose the invention provides an inch rule for reading off distances, wherein there is provided at least one lighting element, wherein the lighting element is so adapted that it lights up the surrounding of the inch rule. The light density and the radiating surface of the lighting element are correspondingly adapted. That inch rule makes it possible to perform measurements even under unfavorable lighting conditions, that is to say in twilight, at night or in a dark region. An advantage with the inch rule is that it is more stable and more rigid than the measuring tape known from the state of the art. Precise measurements are thus possible. The inch rule according to the invention therefore has two functions, namely lighting at least the closer surroundings and measuring distances.
Preferably the at least one lighting element is integrated in the inch rule, that is to say the lighting element is part of the inch rule, wherein, as lateral boundaries of one or more foldable members of the inch rule (preferably the beginning and the end members), light strips can be integrated or mounted throughout at one or both sides of the respective members. Lighting elements with a lighting direction parallel to the inch rule can also be so disposed at the beginning and/or end member of the inch rule that the lighting elements completely mask out the writing on the inch rule.
The at least one lighting element can be battery-operated or solar power-operated. In that respect, the batteries can be rechargeable, in which respect it is conceivable that the entire inch rule is fitted into a charging station. A solar power-operated lighting element is advantageous as it does not require any batteries. Such solar cells are known for example in the case of solar power-operated pocket calculators and take up little space. It is also conceivable that the dimensions of a member of the inch rule are such that it can accommodate a battery, in particular a battery of size AAA.
In particular there is provided a switch device by means of which the at least one lighting element can be switched on and/or off. Thus the lighting element can be switched on or off as required by means of the switch device.
In an embodiment the switch device can be a sliding switch, a pushbutton switch, an electrically controlled switch or a press switch.
The switch or the selected switching device can assume a position that causes the lighting element to flash. The inch rule can therefore also be used as a warning element. The flashing inch rule can be fixed for example to a projecting component to warn others of the obstacle.
The switching device can also assume a position that switches one or more lighting elements on or off or dims the lighting elements. A step switch can also be provided.
A magnetic switch can be provided and the inch rule can be so designed that the at least one lighting element is switched on or off when unfolded.
The inch rule can be designed with one or more foldable members. Preferably the inch rule is a folding inch rule with a plurality of members. The individual members are for example riveted together so that the inch rule can be folded together.
The members or individual members can also be releasably connected together by means of connecting elements, and therefore individual members can be replaced. Press knobs or screws can be used for the releasable connection.
In an embodiment a plurality of lighting elements can be arranged distributed uniformly over the inch rule member. Equally the lighting elements can be arranged distributed irregularly over the member.
The at least one lighting element is preferably partially or entirely embedded in the material of a member.
The material of the member can be transmissive for the light emitted by the at least one lighting element, at least at the position of the at least one lighting element or entirely.
Such lighting elements can also light a rear side of a corporate logo which is left transparent in the uppermost member of the folding inch rule.
The inch rule can be of a length of 0.5 m, 1 m, 2 m, 3 m, 4 m, 5 m etc.
A member of the rule can be magnetic so that it can be caused to adhere to a required location and can rotate in any desired position. The rule is then rotatable through 360°.
A digital clock with an alarm and/or reminder function can be used.
It is also conceivable for the at least one lighting element to be embedded in a flexible sock-like plastic portion. The sock-like plastic portion can then be fitted over the rule. In that way the rule can be retro-fitted with at least one lighting element.